The pacemaker current (or If, or IKf, also referred to as the funny current) is an electric current in the heart that flows through the HCN channel or pacemaker channel. Such channels are important parts of the electrical conduction system of the heart and form a component of the natural pacemaker.
Considering this, what is the role of the voltage gated sodium channels?
Voltage-gated sodium channels are responsible for action potential initiation and propagation in excitable cells, including nerve, muscle, and neuroendocrine cell types [30,32]. They are also expressed at low levels in nonexcitable cells, where their physiological role is unclear .
Why do sodium channels open in action potential?
This change in the membrane potential, called depolarization, will cause the voltage-gated sodium channels to open. Sodium ions will rush in, resulting in a rapid change in the charge. At the peak of the action potential, that area of the neuron is about 40 mV positive.